Scientists encode short movie into DNA of bacteria

13 Julio 2017

While encoding a short film into DNA is impressive, the scientists aren't planning to create some type of cellular-level Netflix app. The Muybridge clip is intended to show the scope for the CRISPR system to turn living cells into recording devices, pulling information from their surroundings and keeping a sequential record within their genome.

Research at UC Berkeley and elsewhere suggests that CRISPR-Cas9 constantly feints with the cell's DNA repair system: as the enzyme cuts at its target site, the cell repairs the DNA, and CRISPR-Cas9 cuts again, repeating this vicious cycle until a mutation arises in the DNA that prevents enzyme binding, at which point the CRISPR-Cas9 molecule moves on to find another binding site. When the scientists retrieved and reconstructed the images by sequencing the bacterial genomes, they got back the same images they put in with about 90 percent accuracy. It's a brief proof-of-concept movie, a sequence of images that illustrates how DNA can be encoded in-and then played back from-DNA in living cells. "We found that if we made the sequences we supplied look like what the system usually grabs from viruses, it would take what we give", Shipman says.

For inserting the image the team relocated the image composed of black and white pixels on the building blocks of DNA known as nucleotides, generating a code associated with the individual pixels of each image.

"We envision a biological memory system that's much smaller and more versatile than today's technologies, which will track many events non-intrusively over time", said Shipman.

"This groundbreaking technology advances the field of DNA-based information storage by leveraging the biological machinery of living cells to record, archive and propagate that information, in addition to potentially providing a new way to study dynamic biological and developmental processes inside the living body", said Wyss Institute Founding Director Donald Ingber, M.D., Ph.D.

DNA is often called the 'blueprint of life'. There are other genome-editing systems that are as precise as CRISPR, but they must be customized for every use and require far more expertise and resources to assemble.

Although this technology could be used in a variety of ways, the researchers ultimately hope to use it to study the brain.

CRISPR is a group of proteins and DNA that act as an immune system in some bacteria, vaccinating them with genetic memories of viral infections.

After sitting in a dish in a lab for a week, the cells grew by dividing into new bacteria cells. It even worked for five frames of the gif. The video is only 36 by 26 pixels, which isn't a lot considering we can encode books and longer movies in synthetic DNA. That's because it contains the instructions needed for an organism to grow, develop, survive and reproduce. "The anti-CRISPR proteins offer opportunities to completely turn off Cas9 as well as fine-tune its activity".

CRISPR was also used to encode this image of a hand into a bacterial genome. This was discovered by sequencing the whole genome of mice that had previously undergone CRISPR gene editing. Article scientists published in the journal Nature.

'Also, the Cas9 protein that they target is not natural in human cells either, so it should be safe. "To me, the most outstanding aspect of these papers, particularly the one that came out in Nature, was the tremendous speed [of the work]".